阴离子型聚氨酯乳液的合成

SYNTHESIS OF ANIONIC POLYURETHANE EMULSION

低聚物多元醇（聚四氢呋喃醚、聚丙二醇醚、聚己二酸乙二醇酯）分别与甲苯二异氰酸酯、二羟甲基丙酸于８０℃下反应２～３ｈ，加入丙酮制得预聚物，尔后在搅拌下加入碱溶液和扩链剂乙二胺，最后在真空下脱除溶剂，即制得阴离子型聚氨酯（ＰＵ）乳液。实验结果表明，用聚四氢呋喃醚或聚己二酸乙二醇酯制备的ＰＵ乳液性能优于聚丙二醇醚，ＰＵ乳液外观呈半透明，总固物含量２０％～３０％，ｐＨ值为７～８，稳定性达１ａ以上；其胶膜的力学性能：拉伸强度２２～２８ＭＰａ，扯断伸长率５５０％～６３０％，撕裂强度５０～６４ｋＮ／ｍ，硬度（邵尔Ａ型）６０～６８度，３００％定伸应力８～１２ＭＰａ。

Oligopolyol[polytetramethylene glycol(PTMG),polypropyleneoxide glycol (PPG) or polyethylene glycol adipate (PEGA)] was reacted with tolylene diisocyanate (TDI) and dimethylol propionic acid (DMPA) respectively for 2～3h at 80℃,then prepolyer was prepared by adding acetone, and prepolymer was mixed by adding alkali solution and crosslinking agent ethylene diamine, finally the anionic polyurethan (PU) emulsion was obtained by removing the solvent under vacuum. The results showed that the properties of PU emulsion prepared from PTMG and PEGA were better than those of from PPG. the appearance of PU emulsion was semitransparent, the total solid content was 20%～30%,pH7～8 and the stability more than 1a.The mechanical properties of its glue film were:tensile strength 22～28MPa,elongation at break 550%～630%, tear strength 50～64KN/m,Shore hardness 60～68A and 300% modulus 8～12MPa.